The invention relates generally to heat exchanging systems and more particularly, to spiral recuperative heat exchanging systems.
Heat exchanging systems are used for efficient heat transfer from one medium to another. The heat exchanging systems are widely used in applications such as space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, and natural gas processing. In general, heat exchanging systems are classified according to their flow arrangement as parallel heat exchanging systems and counter flow heat exchanging systems. In the counter flow heat exchangers, fluids at different temperatures enter the heat exchanger from opposite ends while in the parallel heat exchanging systems the fluids at different temperatures enter from the same direction.
A typical example of a counter flow heat exchanger is a spiral heat exchanger. The spiral heat exchanger may include a pair of flat surfaces that are coiled to form two channels in a counter flow arrangement. The two channels provide a heat exchanging surface to the two fluids. It is generally known that an amount of heat exchanged is directly proportional to the surface area of the heat-exchanging surface. In spiral heat exchangers, the length of the two channels is increased to enhance the surface area of the heat exchanging surface. The enhanced surface area of the heat exchanging surface can lead to an undesirably large size of the heat exchanger. Further, the increase in the length of the two channels results in a longer flow path for the fluid. The longer flow path results in pressure losses of the fluid flowing via the two channels.
On the other hand, maintaining a smaller size of the current spiral heat exchangers results in a smaller length of the two channels, leading to a reduced heat exchanging surface. Consequently, this results in an undesirable efficiency of the heat exchanger.
Furthermore, certain spiral heat exchangers employ reaction chambers for thermal treatment of the gases. Typically, the reaction chambers are disposed partially inside or entirely outside the spiral heat exchangers. In such a structural configuration, the reaction chambers and the spiral heat exchangers are generally connected via tubes. The tubes provide a flow path to the fluid from the spiral heat exchanger to the reaction chamber. The flow path is provided to promote certain reactions within the fluids. The fluid flows from the spiral heat exchanger to the reaction chamber via the tubes resulting in dissipation of heat from the fluid to the environment. Thermal losses in the fluid result in reduction of efficiency of the spiral heat exchanger. In addition, the tubes need to be heavily insulated to reduce the dissipation of heat to the environment and to further reduce the thermal losses. However, providing insulation on the tubes results in undesirable costs of manufacturing the spiral heat exchanger.
Therefore, there is a need for an improved spiral heat exchanger to address one or more aforementioned issues.